The present invention relates to a base anchorage for heavy machinery, in particular converters, comprising an anchoring plate concreted into the base and rigidly connected with at least one bolt, whose end projecting out of the concrete is provided with a screw thread.
In base anchorages of this kind, the connection between the bolt and the anchoring plate is of the greatest importance, since loosening of the bolt would necessitate the demounting of the heavy machinery, the removal of part of the concrete base, the tightening of the bolt and concreting of the anchorage again.
It is known to weld the bolt together with the base plate. In order to ensure a welding connection reliably resistant to any loads, a weldable quality steel has to be used for the bolts, if special measures, such as preheating, etc., are not used. Steels whose carbon content is so low that the formation of cracks during welding is safely avoided are appropriate. Steel frequently used for producing the bolts is, for instance, steel of the quality St 37T according to Austrain standard M 3115, having a carbon content of about 0.16%. Such steels, however, have a low yield point of only 205 N/nm.sup.2 (21 kp/mm.sup.2), so that bolts with large diameters, or a great number of bolts, respectively, have to be provided in order that the forces of the heavy machinery acting on the bolts can be accommodated. However, bolts having large diameters negatively affect the embedding of the anchorage in the concrete base. A further disadvantage is that a space corresponding to the diameter of the bolt and the great number of bolts had to be provided at the foot of the heavy machinery. The known construction therefore consumes excessive space and is heavy.